Ways to avoid bloat when finishing cattle

Managing bloat in finishing cattle

Bloat was always going to be a concern, we needed to be aware of animal welfare and economic losses as well.

We decided we could manage the bloat issue with the application of known management techniques, a summary of these are listed at the end of this article. A visit to Bonavaree Farm, south of Blenheim gave us some confidence about capsules, mowing and co-grazing with sheep. Visits to high performing beef finishing units around the town of Luggate showed us what was possible, not necessarily on lucerne though.

We had an issue with capsules as they are antibiotics. While we were prepared to use capsules, we wanted a system that didn’t need them. Also, mowing is not really an option at Lorne Peak because it is too stony and requires manpower. We even considered hiring a self-propelled vibrating roller, which can be hired quite cheaply in winter when road repairs decline. We imagined we could roll strips, GPS the strips, then do a mow later without destroying the mower. However, this didn’t happen.

Despite the application of known techniques that we could use, we still lost animals to bloat. Simple things like broken ball cocks (diluting bloat oil concentration), broken gate latches, coughed up capsules and cold/wet snaps can trigger problems. On a station the size of Lorne Peak, with only so many staff, these sorts of issues are magnified. What we needed were systems that worked at scale properties with minimal intervention and little risk.

Some points on bloat oil dispensers:

• They are designed for deep cattle troughs, not the sheep/cattle troughs.
• When used in shallower troughs, the dispensing part can sink into the mud at the bottom and stop working.
• Holders can be made to lift the dispenser. These seem to be regarded as toys by cattle.

On smaller farms, the coughed up capsule might be managed by writing the tag numbers on the capsule with a permanent marker. If you find the capsule, you’ll know which beast is at risk.

We decided it would be useful to try and determine when lucerne could be safe after grazing with sheep for a period. Over a period of four days grazing a two break, we did feed quality tests each day with the first being pre graze. We set up 4ha breaks, grazed with 1800 lambs then 120 R2 steers added on day two. What happened is shown in Figure 1.

Perhaps predictably, fiber increased and metabolisable energy (ME) and protein decreased. Now, at 26% acid detergent fiber (ADF) pre graze, this lucerne should be safe for cattle – if they consumed the whole plant. However, cattle and lambs just strip the leaf. Even after the lambs grazing, bloat was an issue. Note: there were no other interventions when this was done. We could have waited longer before introducing the cattle, but growth rates would have been minimal.

This is why mowing works – you take away the ability for livestock to selectively graze.

Figure 1: As part of the B+LNZ research a series of lucerne samples and measurements were taken over two grazing events to quantify when the lucerne might be safe for cattle grazing.

Flaxseed Oil Trial

Another technique we tried was the use of flaxseed oil. Vegetable oil is an old recipe for treating bloated cattle. One of the committee had used flaxseed oil, manually tipped into troughs as a preventative in risky paddocks and conditions. This seemed to work at Lorne Peak but it is labour intensive if you want a constant supply in the trough. This oil is very palatable, unlike other bloat oils, and the first few to drink tend to get the lot of it.

We developed a venturi pump that would deliver a constant flow of oil to a trough. This was tried out on one of the Luggate farms visited. This particular farm produced beef at a significant premium provided, amongst other things, antibiotics and bloat oils were not used. So the flaxseed oil treatment had promise. The venturi pump we had made up just was not robust enough to do the job. Leakages and dirty water were the issues. The venturi developed needs someone to develop it further.

An option to manage bloat, with no intervention, took shape in the form of high tannin companion species. Tannins bind to soluble proteins in the rumen, preventing bloat. We looked into using conventional plant breeding techniques to develop high tannin lucerne here in New Zealand. While not impossible, changing the law to allow high tannin GE lucerne into the country would be the best outcome.

The best option we came up with was Lotus Corniculatus or Birdsfoot Trefoil. Lotus has a similar growth habit to lucerne, dies down in winter and can be weed sprayed. But, it is slower to establish. Seed and inoculant is difficult to get now because demand is low. Don’t get confused with Lotus peduculatus or Lotus major. Pedunculatus has higher concentrations of tannins and is only marginally acceptable to sheep and cattle.

We sowed our Trefoil three ways with lucerne in the last year of the program – as a pure stand, mixed with lucerne and five drill rows of lucerne then two of Lotus. Photos of the result are shown below, in full flower so you can see what’s what.

Pictured above: Five drills Lucerne, then two drills lotus at a B+LNZ project into preventing bloat in beef.

There’s a bit of a story here. The lucerne inoculation failed for unknown reasons. Lotus inoculation was successful. What this did was hold back the establishment of lucerne and probably allowed better lotus establishment, particularly in the lucerne/lotus mixed together treatment.

This paddock on Lorne Peak is one of the harder paddocks; it’s not irrigated, so we are quite pleased with what it looks like now. To overcome the failed inoculation, Matthew sprayed on a heavy dose of inoculant with 200L water/ha, at night and with rain forecast. It worked, and three months later appeared to be a healthy stand as seen above. Whether this is a valid agronomic technique is a moot point.

We have no data as to how cattle performed on this paddock yet. The Innovation farm project came to an end after a short extension because of Covid-19.

So, what happened to the cattle policy at Lorne Peak? The own bred beef calves are still doing a second winter and bull beef is now a significant policy. The bulls are intended as an enterprise that is flexible to cope with the often rapid and large variations in feed availability. The lucerne focus is sheep as this is where the best overall returns are. Notably, better hgt lambing performance, higher weaning and mating weights for ewes and faster lamb growth, both pre and post wean. With up to 700ha of lucerne and now two pivots commissioned, the beef cattle have a bigger role to play on the better hill country. These changes in policy direction came from extensive Farmax modelling.

For those folk where cattle finishing could fit well into a lucerne programme, seriously consider companion plants as a low intervention management tool for bloat.

Summary of bloat control options

• Capsules (Monensin): Approx $20 excl. 100 days, regurgitation an issue and highly toxic to dogs. Can write ear tag number on body of capsule- tag pen. Can’t use under 250kgLW. Is an antibiotic, processor resistance. About 20c/day for protection.
• Rumenox (granular form of Monensin): Designed to be delivered via Dosatron. Cost about 8c/day for adult cattle. Not including the cost of Dosatron.
  Dog toxicity, greater risk as have easy access to water.
• Bloatenz (via Peta Dispensers) (Alcohol ethoxylate): Approx. $200 to $300 for dispenser depending 24hr or 48hr type. Adult cattle consume about 9cc/day, calves about 4.5cc/day. Costs $6.50/L purchased as 200L. Adult cattle about 6c/day and calves about 3c/day for protection. Not including cost of dispensers. Highly toxic to horses but safe with sheep and dogs. Note: not safe for pre-ruminant calves and lambs. May have palatability issues, at least initially.
• Dispensers designed to float in deep dairy troughs, but can be used in shallow troughs with a holder attached to the side of the trough which keeps the dispenser an inch or two out on the muck at the bottom of the trough. No commercially made holders available.
• Vegetable oil: A well known cure for clinical bloat but may be useful for prevention in low doses daily. Flaxseed oil is being used at Lorne Peak, it is very palatable. No automatic dispenser available so rely on manual dosing. A better venturi pump is needed. Costs $3/L (Midlands Oils) and at 30cc/ day is 9c/day. Plausible solution but unproven.
• Bloat blocks: Fairly sure these are not made any more, even so, these would be unreliable.
• Salt: Anecdotal evidence salt supplementation may alleviate bloat by buffering rumen pH. When relying on salt blocks, calves consumed about 2grams/animal/day. When offered loose salt, intake increased to 30 grams. Trough treatments are possibly the best solution.

Bloat management options

• Companion species with lucerne to provide roughage and, preferably, tannin (Lotus corniculatus and plantain.
• High tannin lucerne – would require change in New Zealand law.
• Transition takes time.
• Never shift hungry cattle, use a follow up mob to clean up.
• Shift mid day – no dew and higher carbohydrate.
• Avoid big changes in feed quality, i.e., leaving animals to clean up then shift, will also be hungry at shift.
• Small breaks are better, less opportunity to preferentially graze.
• Graze lucerne close to maturity normally recommended, but more opportunity to strip leaves.
• Co graze with leader/follower systems with sheep may reduce risk.
• Spring growth is more dangerous. But rapid growth from rain after dry is equally dangerous.
• Mowing strips works with R2 cattle but experience at Lorne Peak shows calves avoid mown areas.
• Provide roughage, need to consider practicality.
• Clostridial deaths may appear to be bloat. 10:1 vaccine is cheap insurance.